Retrieving tool



S. F. DE CORDOVA RETRIEVING TOOL Feb. 11, 1964 Filed May 8, 1957INVENTOR. Jamue/ E 0 9 Cora 0 v0 BY gimp/J m ATTOFA/EKS United StatesPatent 3,129,371 RETREVING TOOL Samuel F. de (Iordova, R0. Box 4%,Jennings, La. Filed May is, 1957, Ser. No. 657,954 Claims. (Cl. 166-55)My invention relates to a retrieving tool, and more particularly, to atool for retrieving from a well devices attached above the bottom of thewell against longitudinal displacement.

In various operations designed to condition oil wells or the like forproduction, it is necessary to pack-oil the well at a given depth toprevent the flow of fluids thereby. Well packers have been designed withserrated slips or other means adapted to grip the internal wall of thecasing to fix at a selected depth an expanda le packing element orsimilar device. Certain well packers, such as permanent or cementingpackers, are designed to resist fluid pressures from either directionlongitudinal of the Well and, as such, are designed to be locked againstupward or downward movement therein. Consequently, once set, a packercannot be raised or lowered by conventional means and should subsequentoperations dee it desirable to remove the packer from the well, it hasheretofore been necessary to mill away the entire well packer structureand then to retrieve the broken pieces which fall to the bottom of thewell by conventional fishing devices of the magnetic or hydraulic type.

It is, therefore, an object of my invention to provide an apparatus forremoving permanent or cementing packers or similar devices lockedagainst axial movement with any well, While causing a minimum amount ofdamage thereto.

It is a further object of my invention to provide an apparatus for theremoval or" set packers which apparatus substantially eliminate thenecessity of fishing for broken particles of the packer.

It is a further object of my invention to provide a retrieving toolwhich permits the circulation of fluid therethrough while retrieving anobject which plugs the well therebelow.

It is a further object of my invention to provide a tool retrievingapparatus which is economical to construct and simple and eflicient inoperation.

My retrieving tool comprises a grappling device adapted to grippositively a portion of the lodged tool to pre vent it from falling tothe bottom of the well when its attachment to the well casing issubsequently severed, and a cutting shoe to mill away at least thoseelements of the packer gripping the well casing against upward movementthereof. During the milling operation circulation of drilling fluid isunimpeded and milled chips and pieces of the packer are carried upwardlytherewith to the surface. After the upper slips or well casing grippersare milled away, the retrieving tool is raised by means of the drillstring to which it is attached whereby the grappling device pulls thepacker upwardly to remove it from the well.

Other objects and novel features of the invention will become apparentfrom the following specification when viewed in connection with theaccompanying drawings wherein:

FIG. 1 is a vertical section of the improved retrieving tool incondition for engagement with the fish; and

FIG. 2 is a vertical section of my improved retrieving tool preparatoryto removal of the fish from the well.

Referring to the drawings, reference numeral 1 denotes a well casingwithin which is set a well packer 2 so as to resist displacement thereofin either axial direction. The particular manner in which such wellpackers are set is not particularly material to this invention, but forpurposes of illustration I have shown a typical structural arrangementthereof. In this embodiment, the well packer 2 includes a centralmandrel 3 having a sub 4 at the upper end adapted for engagement byexternal threads on a drill string, of the type shown at 5 below thepacker, so that the packer can be raised, lowered or rotated therewithin a thread tightening direction. The lower portion of the mandrel 3 isenlarged radially to present an external shoulder 6 above which areslidably carried on the mandrel 3 lower slips 7 and engagingfrusto-conical slip expanders 3. Slidable on the upper portion ofmandrel 3 is a sleeve 9 on which is carried upper slips 1% engageablewith upper slip expander wedges 11. An expandable packing element 12 iscarried on the sleeve between the slip expanders 8 and 11. To set thepacker at a selected depth within the well casing 1, the sleeve 9 isforced down along mandrel 3 to force upper slips 10' over its slipexpander 11 to lock the packer against upward movement and then themandrel 3 is raised to force the lower slip 7 upwardly over its expander55 by means of shoulder 6 thus expanding the lower slips to grip thecasing wall 1 against downward movement. During expansion of the lowerslips 7 the upward thrust against the lower slip expander 8 forces ittoward the upper expander 11 to compress axially the expansible packerelement 12 and expand it radially to seal off the casing 1 against fluidflow. It is apparent that with the upper slips resisting any force thatmay tend to pull the well packer up through the casing and with thelower slips resisting downwmd movement, the well packer cannotconveniently be removed from the well by conventional surface-controlledmeans.

My retrieving tool 259 comprises a mandrel or main tubular body 21threaded or otherwise adapted at its upper end 22 for attachment to astring of tubing (not shown). At the lower open end of the body 21 issecured a milling shoe 23 for a purpose to be hereinafter described.Within the body at the central portion thereof is an internal shoulder24. If desired, the tubular body may be formed in two sections, asshown, and threaded together at 25 for ease of construction andassembly. Supported within the tubular body 21 is a pilot or a grapplerod 26 having a flange or other radial extension 27 at its upper endadapted to be supported on the internal shoulder 24 in the tubular body,as shown in FIG. 1. Both the grapple rod 26 and the integral flange 27are sufficiently small in size as to render the grapple rod 26 freelyslidable within the tubular body 21 above the lower limits dictated byflange Z7 and shoulder 24. Along the shank of grapple rod 26 immediatelybelow the flange 27 are carried axial keys 28 receivable in keyways 29cut into the internal shoulder 24. Consequently, with the flange 27 atrest on shoulder 24 with the keys so engaged, rotation of the tubularbody 21 will produce concomitant. rotation of grapple rod 26.Additionally, in order to prevent initially any sliding movement ofgrapple rod 26 within tubular body 21 I provide shear pins 39 securingit thereto as for example at the flange 27. At the lower end of rod 26is a grapple 31 here illustrated as an externally threaded memberadapted to engage positively the sub 4 at the upper end of the packer 2for which purpose the rod 26 is of suflicient length that grapple 31extends below the milling shoe 23 enough so that even when the grapplehas fully gripped the packer there is clearance between the milling shoe23 and the top 9 of the packer.

I do not intend that the structure of my device be limited to thespecific form of grapple shown. It will become apparent that any form ofattaching means effected by the rotation of grapple rod 26 impartedthrough its keyed attachment with the tubular body 21, such as a J-slotattachment, a bayonet slot or the like will satisfy the requirements ofmy retrieving tool. It is further apparent that my invention is notlimited to the specific fiange and shoulder means 27 and 24 shown tosupport the grapple rod within the tubular body. The radial extension 27at the top of rod as need not be completely annular but may be segmentalin which case it could itself be adapted to be received and supported inslots cut partially through shoulder 24 to provide the rotary coupling.Other means and devices may be substituted but the significant featureis the provision of a member to suspend the grapple rod below the loweropen end of the tubular body to prevent it from falling therethroughtogether with means for imparting through the tubular body 21 to thegrapple rod 26 a particular motion requisite to effect attachment to thefish lodged within the well casing 1.

Preferably, a fluid passage 32 is provided through the grapple rod 26 sothat, if necessary or desirable, a jet of fluid may be directed againstthe upper end of the lodged fish to wash away any mud or the like thatmay otherwise impede connection of the grapple with the fish.

When full connection between the grapple rod 26 and the fish 2 isestablished the clearance between the lower end of milling shoe 23 andthe upper end 9 of packer should be such that subsequent downwardmovement of the tubular body will not only shear the pins 30 but willmove shoulder 24 free of the keys 28 whereby further rotation of tubularbody 21 will not affect the grapple rod 26. Such further rotation causesmilling shoe 23 to begin cutting away the sleeve 9 and other portions ofthe well packer surrounding the mandrel 3 until the upper slips it) arecut away or otherwise inactivated as shown in FIG. 2. Thereafter, thetubing string may again be raised to raise the tubular body 21 liftingshoulder 24 into engagement with its flange 27 and thereby raisinggrapple rod 26 with the freed packer from the well.

During the milling operation, I provide for circulation of drillingfluid around flange 27 and down through the open end of tubular body 21to carry chips upwardly around the tubular body 21 to the surface. Tofacilitate flow of drilling fluid grooves 33 may be cut tluough upperflange 27.

In operation of the device my retrieving tool is lowered into the casinguntil the lower end of the tool Zll engages the upper end of the packer2 lodged within the casing 1. Since the tubular body is guided againstappreciable radial movement by virtue of its limited clearance withinthe casing 2 and since the grapple rod 26 is centrally disposed withinthe tubular body 21 by the shear pins 30 and the key attachment Z8, 29,the rod will be guided into the centrally disposed internally threadedsub 4 of the packer. Thereafter, the retrieving tool body 21 is rotatedto rotate the grapple rod 26 and thread the attaching member 31 onto thesub 4 of the packer. After the connection with the well packer isestablished, the drill string and, hence, the tubular body 21 are drivendownwardly to fracture the shear pins 36 and to slide the keyway 29 freeof the keys 28 to render the tubular body rotatable on the grapple rod26. Thereafter rotation of tubular body 21 will cause the milling shoe23 to cut away the outer sleeve 9 and the upper slips with the tubularbody 21 rotating and sliding down over grapple rod 26. Obviously, thewidth of the milling shoe must be such that it Will not sever the fishfrom the grappling means, and in the structure illustrated the mandrel 3and sub 4 are left substantially intact. The mill 2.3 is centralizedwithin the casing 2 by its limited radial clearance of the mill 23relative to the casing 1 preventing any wandering thereof that wouldotherwise cause unnecessary damage to the mandrel such as would disruptthe connection with the grapple rod 26. After the milling shoe has cutaway or inactivated the upper slip assembly, the expansible sleeveoffers no appreciable resistance to the lower slip expander 8 and,therefore, it is substantially ineffective to resist movei ment of thepacker and to wedge the lower slips 7 outward. Consequently, the tubingstring may be raised until the shoulder 24 again engages the flange 27to lift the grapple rod 26 and the packer from the well.

Throughout the milling operation, drilling fiuid may be circulatedaround the grapple rod 26 and out through the lower end of the millingshoe 2? to carry chips and pieces milled from the packer upward aroundthe outside of the tubular body and tubing string to the surface. Withthe expansible element preventing passage of said chips downward to thebottom of the casing, there is no necessity to lower a magnet or otherfishing device to extract such pieces from the well.

While a specific embodiment of my invention has been shown anddescribed, many variations in structure within the scope of my inventiondefined by the following claims are possible and contemplated. There isno intention, therefore, of limitation to the exact details shown anddescribed.

Having described my invention, I claim:

1. Apparatus for retrieving a fish from a well casing, said fish beingsecured against upward movement above the bottom of said well casing byholding means attaching said fish to the wall of said well casing, saidapparatus comprising a tubular body open at the low-er end thereof, agrapple rod within said body, support means extending radially from theupper portion of said grapple rod, stop means within said tubular bodyengageable with said support means to suspend said grapple rod in anactive position with the lower end thereof extending below said lowerend of the body, coupling means connecting said grapple rod while insaid active position to said body for rotation therewith, attachng meanson the lower end of said grapple rod for attaching said rod to said fishupon engagement therewith and rotation relative thereto, said couplingmeans being releasable when said grapple rod is attached to said fish topermit downward movement of said body relative to said grapple rod intoengagement with said fish, and a cutting member on the lower open end ofsaid body adapted to sever said holding means after engagementtherewith.

2 Apparatus for retrieving a fish from a well casing, said fish beingsecured to the wall of said well casing above the bottom thereof, saidapparatus comprising a tubular body open at the lower end thereof, agrapple rod within said body, radial extensions near the upper end ofsaid grapple rod, stop means within said body engaging wtih said radialextensions to support said grapple rod with the lower end thereofextending below said open lower end, coupling means engageable only whensaid radial extensions are engaged by said stop means to connect saidgrapple rod for rotation with said body, means interconnecting saidgrapple rod and said body to prevent relative sliding movementtherebetween, attaching means on the lower end of said grapple rod forattaching said rod to said fish upon engagement therewith and rotationrelative thereto, said interconnectin means being releasable when saidgrapple rod is attached to said fish to render said body slidable oversaid grapple rod for downward movement into engagement with said fish,and a cutting member on the lower open end of said body.

3. An apparatus for retrieving a fish from a well easing, said fishbeing supported above the bottom of the well casing by holding meansfirmly attaching said fish to the wall of said we 1 casing, saidapparatus comprising,

(a) a tubular body open at the lower end thereof,

(b) a grapple rod movable longitudinally within said body,

(c) attaching means on the lower end of said grapple rod for attachingsaid rod to said fish upon engagernent therewith and rotation relativethereto,

(d) coupling means locking said body and said grapple rod againstrelative longitudinal m vement and for rotation together whereby saidattaching means on said grapple rod may be engaged with said fish,

(2) said coupling means being releasable when said grapple rod isattached to said fish and upon downward movement of said body relativeto said grapple rod to render said body longitudinally movable androtatable relative to said grapple rod.

(1) stop means on said body engageable by a portion of said grapple rodto prevent said grapple rod from sliding out of said open lower end, and

(g) a cutting member on the lower open end of said body adapted to seversaid holding means after engagement therewith.

4. Apparatus for retrieving from a well casing a fish including acentral portion and a gripping means on the outside thereof locking saidcentral portion to the wall of the well casing against upwarddisplacement thereof, said apparatus comprising,

(a) a tubular body having an open lower end,

(1)) a grapple rod slidable within said tubular body,

() radially extending shoulder means on said grapple rod,

((1) stop means on said body to engage said shoulder means and therebylimit downward sliding movement of said grapple rod relative to saidbody,

(6) coupling means locking said body and said grapple rod againstrelative movement only when said shoulder means and said stop means areengaged,

(f) attaching means on the lower end of said grapple rod for attachingsaid grapple rod to said central portion upon rotation of said body andgrapple rod,

(g) said coupling means including shear pin means which is releasablewhen said grapple rod is attached to said central portion whereby saidbody may then move longitudinally and rotatably relative to said grapplerod, and

(h) cutting means on the lower end of said body for severing saidgripping means after engagement therewith and upon continued rotationand longitudinal movement of said body relative to said grapple rod.

in a well bore, said apparatus comprising,

(a) a tubular body having an open lower end,

(b) a grapple rod within said tubular body,

(0) coupling means normally coupling said grapple rod to said tubularbody coaxial therewith with the lower end of said grapple rod extendingbelow the lower end of said tubular body,

(d) said body being longitudinally movable and rotatable relative tosaid grapple rod when said coupling means are released,

(e) a radially extending shoulder on said grapple rod,

(7) a stop member on said body engageable with said shoulder to preventsaid grapple rod from passing through the open lower end of said tubularbody,

g) attaching means on the lower end of said grapple rod for attachingsaid grapple rod to said fish upon rotation of said body and saidgrapple rod,

(11) said coupling means including shear pin means which is releasablewhen said grapple rod is attached to said central portion whereby saidbody may then move longitudinally and rotatably relative to said grapplerod, and

(1') cutting means on the lower end of said tubular body for severingsaid fish upon continued rotation and longitudinal movement of said bodyrelative to said grapple rod.

References Cited in the file of this patent UNITED STATES PATENTS2,261,564 Robichaux et a1 Nov. 4, 1941 2,481,637 Yancey Sept. 13, 19492,762,438 Naylor Sept. 11, 1956 2,804,148 Schremp et al Aug. 27, 19572,804,151 Le Bus Aug. 27, 1957 2,832,423 Hall Apr. 29, 1958

1. APPARATUS FOR RETRIEVING A FISH FROM A WELL CASING, SAID FISH BEINGSECURED AGAINST UPWARD MOVEMENT ABOVE THE BOTTOM OF SAID WELL CASING BYHOLDING MEANS ATTACHING SAID FISH TO THE WALL OF SAID WELL CASING, SAIDAPPARATUS COMPRISING A TUBULAR BODY OPEN AT THE LOWER END THEREOF, AGRAPPLE ROD WITHIN SAID BODY, SUPPORT MEANS EXTENDING RADIALLY FROM THEUPPER PORTION OF SAID GRAPPLE ROD, STOP MEANS WITHIN SAID TUBULAR BODYENGAGEABLE WITH SAID SUPPORT MEANS TO SUSPEND SAID GRAPPLE ROD IN ANACTIVE POSITION WITH THE LOWER END THEREOF EXTENDING BELOW SAID LOWEREND OF THE BODY, COUPLING MEANS CONNECTING SAID GRAPPLE ROD WHILE INSAID ACTIVE POSITION TO SAID BODY FOR ROTATION THEREWITH, ATTACHINGMEANS ON THE LOWER END OF SAID GRAPPLE ROD FOR ATTACHING SAID ROD TOSAID FISH UPON ENGAGEMENT THEREWITH AND ROTATION RELATIVE THERETO, SAIDCOUPLING MEANS BEING RELEASABLE WHEN SAID GRAPPLE ROD IS ATTACHED TOSAID FISH TO PERMIT DOWNWARD MOVEMENT OF SAID BODY RELATIVE TO SAIDGRAPPLE ROD INTO ENGAGEMENT WITH SAID BODY ADAPTED TO SEVER SAID HOLDINGMEANS AFTER ENGAGEMENT THEREWITH.